Effects of Absolute Humidity, Relative Humidity, Temperature, and Wind Speed on Influenza Activity in Toronto, Ontario, Canada

ABSTRACT The occurrence of influenza in different climates has been shown to be associated with multiple meteorological factors. The incidence of influenza has been reported to increase during rainy seasons in tropical climates and during the dry, cold months of winter in temperate climates. This study was designed to explore the role of absolute humidity (AH), relative humidity (RH), temperature, and wind speed (WS) on influenza activity in the Toronto, ON, Canada, area. Environmental data obtained from four meteorological stations in the Toronto area over the period from 1 January 2010 to 31 December 2015 were linked to patient influenza data obtained for the same locality and period. Data were analyzed using correlation, negative binomial regressions with linear predictors, and splines to capture the nonlinear relationship between exposure and outcomes. Our study found a negative association of both AH and temperature with influenza A and B virus infections. The effect of RH on influenza A and B viruses was controversial. Temperature fluctuation was associated with increased numbers of influenza B virus infections. Influenza virus was less likely to be detected from community patients than from patients tested as part of an institutional outbreak investigation. This could be more indicative of nosocomial transmission rather than climactic factors. The nonlinear nature of the relationship of influenza A virus with temperature and of influenza B virus with AH, RH, and temperature could explain the complexity and variation between influenza A and B virus infections. Predicting influenza activity is important for the timing of implementation of disease prevention and control measures as well as for resource allocation. IMPORTANCE This study examined the relationship between environmental factors and the occurrence of influenza in general. Since the seasonality of influenza A and B viruses is different in most temperate climates, we also examined each influenza virus separately. This study reports a negative association of both absolute humidity and temperature with influenza A and B viruses and tries to understand the controversial effect of RH on influenza A and B viruses. This study reports a nonlinear relation between influenza A and B viruses with temperature and influenza B virus with absolute and relative humidity. The nonlinear nature of these relations could explain the complexity and difference in seasonality between influenza A and B viruses, with the latter predominating later in the season. Separating community-based specimens from those obtained during outbreaks was also a novel approach in this research. These findings provide a further understanding of influenza virus transmission in temperate climates.

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Chimeric Hemagglutinin Constructs Induce Broad Protection against Influenza B Virus Challenge in the Mouse Model

Journal of Virology ◽

10.1128/jvi.00286-17 ◽

2017 ◽

Vol 91 (12) ◽

Cited By ~ 36

Author(s):

Megan E. Ermler ◽

Ericka Kirkpatrick ◽

Weina Sun ◽

Rong Hai ◽

Fatima Amanat ◽

...

Keyword(s):

Influenza Virus ◽

Influenza A ◽

Antiviral Drug ◽

Antigenic Drift ◽

Influenza B Virus ◽

Influenza B ◽

Virus Infections ◽

Lethal Challenge ◽

Public Health Burden ◽

B Virus

ABSTRACT Seasonal influenza virus epidemics represent a significant public health burden. Approximately 25% of all influenza virus infections are caused by type B viruses, and these infections can be severe, especially in children. Current influenza virus vaccines are an effective prophylaxis against infection but are impacted by rapid antigenic drift, which can lead to mismatches between vaccine strains and circulating strains. Here, we describe a broadly protective vaccine candidate based on chimeric hemagglutinins, consisting of globular head domains from exotic influenza A viruses and stalk domains from influenza B viruses. Sequential vaccination with these constructs in mice leads to the induction of broadly reactive antibodies that bind to the conserved stalk domain of influenza B virus hemagglutinin. Vaccinated mice are protected from lethal challenge with diverse influenza B viruses. Results from serum transfer experiments and antibody-dependent cell-mediated cytotoxicity (ADCC) assays indicate that this protection is antibody mediated and based on Fc effector functions. The present data suggest that chimeric hemagglutinin-based vaccination is a viable strategy to broadly protect against influenza B virus infection. IMPORTANCE While current influenza virus vaccines are effective, they are affected by mismatches between vaccine strains and circulating strains. Furthermore, the antiviral drug oseltamivir is less effective for treating influenza B virus infections than for treating influenza A virus infections. A vaccine that induces broad and long-lasting protection against influenza B viruses is therefore urgently needed.

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Severe Influenza Virus Infection in Children Admitted to the PICU: Comparison of Influenza A and Influenza B Virus Infection

Journal of Medical Virology ◽

10.1002/jmv.27400 ◽

2021 ◽

Author(s):

Pınar YAZICI ÖZKAYA ◽

Eşe Eda TURANLI ◽

Hamdi METİN ◽

Ayça Aydın UYSAL ◽

Candan ÇİÇEK ◽

...

Keyword(s):

Influenza Virus ◽

Virus Infection ◽

Influenza A ◽

Influenza Virus Infection ◽

Influenza B Virus ◽

Influenza B ◽

Severe Influenza ◽

B Virus

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Haemagglutination-inhibition antibodies against influenza A and influenza B in maternal and neonatal sera

Journal of Hygiene ◽

10.1017/s0022172400053353 ◽

1978 ◽

Vol 80 (1) ◽

pp. 13-19 ◽

Cited By ~ 6

Author(s):

N. Masurel ◽

J. I. de Bruijne ◽

H. A. Beuningh ◽

H. J. A. Schouten

Keyword(s):

Influenza Virus ◽

Maternal Age ◽

Influenza A ◽

Haemagglutination Inhibition ◽

Influenza Viruses ◽

Influenza B Virus ◽

Influenza B ◽

B Virus ◽

Duration Of Pregnancy ◽

Pregnancy And Birth

SUMMARYHaemagglutination inhibition (HI) antibodies against the influenza viruses A/Hong Kong/8/68 (H3N2) and B/Nederland/77/66 were determined in 420 paired sera from mothers and newborns (umbilical cord sera), sampled in 1970–1.A higher concentration of antibodies against influenza A virus was found more frequently in neonatal than in maternal sera. By contrast, low titres against influenza B virus were more frequently observed in neonatal than in maternal sera. Maternal age, duration of pregnancy, and birth-weight did not affect the results of the tests.It is suggested that the titre of the newborn against an epidemic influenza virus can be predicted from that of the mother. Furthermore, the maternal titre may be an indication of the susceptibility of the newborn infant to influenza infections.

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Epidemiological and virological assessment of influenza activity in Europe during the winter 2005-2006

Eurosurveillance ◽

10.2807/esm.12.09.00733-en ◽

2007 ◽

Vol 12 (9) ◽

pp. 11-12 ◽

Cited By ~ 15

Author(s):

A Meijer ◽

T J Meerhoff ◽

L. E. Meuwissen ◽

J Van Der Velden ◽

W J Paget ◽

...

Keyword(s):

Influenza A ◽

New Caledonia ◽

Influenza B Virus ◽

Random Pattern ◽

Clinical Activity ◽

Influenza B ◽

Influenza A Viruses ◽

B Virus ◽

Influenza Activity ◽

Spread Pattern

Influenza activity in Europe during the winter 2005-2006 started late January - early February 2006 and first occurred in the Netherlands, France, Greece and England. Subsequently, countries were affected in a random pattern across Europe and the period of influenza activity lasted till the end of April. In contrast to the winter seasons in the period 2001-2005, no west-east pattern was detected. In 12 out of 23 countries, the consultation rates for influenza-like illness or acute respiratory infection in the winter 2005-2006 were similar or higher than in the winter 2004-2005, despite a dominance of influenza B viruses that normally cause milder disease than influenza A viruses. In the remaining 11 countries the consultation rates were lower to much lower than in the winter 2004-2005. The highest consultation rates were usually observed among children aged 0-14. The circulating influenza virus types and subtypes were distributed heterogeneously across Europe. Although the figures for total virus detections in Europe indicated a predominance of influenza B virus (58% of all virus detections), in many countries influenza B virus was predominant only early in the winter, whilst later there was a marked increase in influenza A virus detections. Among the countries where influenza A viruses were co-dominant with B viruses (9/29) or were predominant (4/29), the dominant influenza A subtype was H3 in seven countries and H1 in four countries. The vast majority of characterised influenza B viruses (90%) were similar to the B/Victoria/2/87 lineage of influenza B viruses that re-emerged in Europe in the winter 2004-2005 but were not included in the vaccine for the influenza season 2005-2006. This might help to explain the dominance of influenza B viruses in many countries in Europe during the winter 2005-2006. The influenza A(H3) and A(H1) viruses were similar to the reference strains included in the 2005-2006 vaccine, A/California/7/2004 (H3N2) and A/New Caledonia/20/99 (H1N1), respectively. In conclusion, the 2005-2006 influenza epidemic in Europe was characterised by moderate clinical activity, a heterogeneous spread pattern across Europe, and a variable virus dominance by country, although an overall dominance of influenza B viruses that did not match the virus strain included in the vaccine was observed.

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Serum High-Mobility-Group Box 1 as a Biomarker and a Therapeutic Target during Respiratory Virus Infections

mBio ◽

10.1128/mbio.00246-18 ◽

2018 ◽

Vol 9 (2) ◽

Cited By ~ 16

Author(s):

Mira C. Patel ◽

Kari Ann Shirey ◽

Marina S. Boukhvalova ◽

Stefanie N. Vogel ◽

Jorge C. G. Blanco

Keyword(s):

Influenza Virus ◽

Virus Infection ◽

Influenza A ◽

Influenza Virus Infection ◽

High Mobility ◽

Influenza B Virus ◽

Influenza B ◽

Lung Pathology ◽

B Virus ◽

Cotton Rats

ABSTRACT Host-derived “danger-associated molecular patterns” (DAMPs) contribute to innate immune responses and serve as markers of disease progression and severity for inflammatory and infectious diseases. There is accumulating evidence that generation of DAMPs such as oxidized phospholipids and high-mobility-group box 1 (HMGB1) during influenza virus infection leads to acute lung injury (ALI). Treatment of influenza virus-infected mice and cotton rats with the Toll-like receptor 4 (TLR4) antagonist Eritoran blocked DAMP accumulation and ameliorated influenza virus-induced ALI. However, changes in systemic HMGB1 kinetics during the course of influenza virus infection in animal models and humans have yet to establish an association of HMGB1 release with influenza virus infection. To this end, we used the cotton rat model that is permissive to nonadapted strains of influenza A and B viruses, respiratory syncytial virus (RSV), and human rhinoviruses (HRVs). Serum HMGB1 levels were measured by an enzyme-linked immunosorbent assay (ELISA) prior to infection until day 14 or 18 post-infection. Infection with either influenza A or B virus resulted in a robust increase in serum HMGB1 levels that decreased by days 14 to 18. Inoculation with the live attenuated vaccine FluMist resulted in HMGB1 levels that were significantly lower than those with infection with live influenza viruses. RSV and HRVs showed profiles of serum HMGB1 induction that were consistent with their replication and degree of lung pathology in cotton rats. We further showed that therapeutic treatment with Eritoran of cotton rats infected with influenza B virus significantly blunted serum HMGB1 levels and improved lung pathology, without inhibiting virus replication. These findings support the use of drugs that block HMGB1 to combat influenza virus-induced ALI. IMPORTANCE Influenza virus is a common infectious agent causing serious seasonal epidemics, and there is urgent need to develop an alternative treatment modality for influenza virus infection. Recently, host-derived DAMPs, such as oxidized phospholipids and HMGB1, were shown to be generated during influenza virus infection and cause ALI. To establish a clear link between influenza virus infection and HMGB1 as a biomarker, we have systematically analyzed temporal patterns of serum HMGB1 release in cotton rats infected with nonadapted strains of influenza A and B viruses and compared these patterns with a live attenuated influenza vaccine and infection by other respiratory viruses. Towards development of a new therapeutic modality, we show herein that blocking serum HMGB1 levels by Eritoran improves lung pathology in influenza B virus-infected cotton rats. Our study is the first report of systemic HMGB1 as a potential biomarker of severity in respiratory virus infections and confirms that drugs that block virus-induced HMGB1 ameliorate ALI.

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Detection of severe acute respiratory syndrome coronavirus 2 and influenza viruses based on CRISPR-Cas12a

Experimental Biology and Medicine ◽

10.1177/1535370220963793 ◽

2020 ◽

pp. 153537022096379

Author(s):

Oraphan Mayuramart ◽

Pattaraporn Nimsamer ◽

Somruthai Rattanaburi ◽

Naphat Chantaravisoot ◽

Kritsada Khongnomnan ◽

...

Keyword(s):

Influenza Virus ◽

Severe Acute Respiratory Syndrome ◽

Influenza A ◽

Limit Of Detection ◽

Cross Reactivity ◽

Influenza Viruses ◽

Influenza B Virus ◽

Influenza B ◽

Influenza Virus A ◽

B Virus

Due to the common symptoms of COVID-19, patients are similar to influenza-like illness. Therefore, the detection method would be crucial to discriminate between SARS-CoV-2 and influenza virus-infected patients. In this study, CRISPR-Cas12a-based detection was applied for detection of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), influenza A virus, and influenza B virus which would be a practical and attractive application for screening of patients with COVID-19 and influenza in areas with limited resources. The limit of detection for SARS-CoV-2, influenza A, and influenza B detection was 10, 103, and 103 copies/reaction, respectively. Moreover, the assays yielded no cross-reactivity against other respiratory viruses. The results revealed that the detection of influenza virus and SARS-CoV-2 by using RT-RPA and CRISPR-Cas12a technology reaches 96.23% sensitivity and 100% specificity for SARS-CoV-2 detection. The sensitivity for influenza virus A and B detections was 85.07% and 94.87%, respectively. In addition, the specificity for influenza virus A and B detections was approximately 96%. In conclusion, the RT-RPA with CRISPR-Cas12a assay was an effective method for the screening of influenza viruses and SARS-CoV-2 which could be applied to detect other infectious diseases in the future.

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Co-circulation of the two influenza B lineages during 13 consecutive influenza surveillance seasons in Italy, 2004–2017

BMC Infectious Diseases ◽

10.1186/s12879-019-4621-z ◽

2019 ◽

Vol 19 (1) ◽

Cited By ~ 6

Author(s):

Simona Puzelli ◽

◽

Angela Di Martino ◽

Marzia Facchini ◽

Concetta Fabiani ◽

...

Keyword(s):

Influenza A ◽

Respiratory Illness ◽

Influenza Surveillance ◽

Influenza B Virus ◽

Influenza B ◽

Virus Infections ◽

Ha Gene ◽

B Virus ◽

B Lineage ◽

Trivalent Vaccine

Abstract Background Since 1985, two antigenically distinct lineages of influenza B viruses (Victoria-like and Yamagata-like) have circulated globally. Trivalent seasonal influenza vaccines contain two circulating influenza A strains but a single B strain and thus provide limited immunity against circulating B strains of the lineage not included in the vaccine. In this study, we describe the characteristics of influenza B viruses that caused respiratory illness in the population in Italy over 13 consecutive seasons of virological surveillance, and the match between the predominant influenza B lineage and the vaccine B lineage, in each season. Methods From 2004 to 2017, 26,886 laboratory-confirmed influenza cases were registered in Italy, of which 18.7% were type B. Among them, the lineage of 2465 strains (49%) was retrieved or characterized in this study by a real-time RT-PCR assay and/or sequencing of the hemagglutinin (HA) gene. Results Co-circulation of both B lineages was observed each season, although in different proportions every year. Overall, viruses of B/Victoria and B/Yamagata lineages caused 53.3 and 46.7% of influenza B infections, respectively. A higher proportion of infections with both lineages was detected in children, and there was a declining frequency of B/Victoria detections with age. A mismatch between the vaccine and the predominant influenza B lineage occurred in eight out of thirteen influenza seasons under study. Considering the seasons when B accounted for > 20% of all laboratory-confirmed influenza cases, a mismatch was observed in four out of six seasons. Phylogenetic analysis of the HA1 domain confirmed the co-circulation of both lineages and revealed a mixed circulation of distinct evolutionary viral variants, with different levels of match to the vaccine strains. Conclusions This study contributes to the understanding of the circulation of influenza B viruses in Italy. We found a continuous co-circulation of both B lineages in the period 2004–2017, and determined that children were particularly vulnerable to Victoria-lineage influenza B virus infections. An influenza B lineage mismatch with the trivalent vaccine occurred in about two-thirds of cases.

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A comparison of influenza and respiratory syncytial virus infections among infants admitted to hospital with acute respiratory infections

Journal of Hygiene ◽

10.1017/s0022172400055765 ◽

1976 ◽

Vol 77 (3) ◽

pp. 383-392 ◽

Cited By ~ 16

Author(s):

E. O. Caul ◽

D. K. Waller ◽

S. K. R. Clarke ◽

B. D. Corner

Keyword(s):

Influenza Virus ◽

Respiratory Syncytial Virus ◽

Rural Areas ◽

Influenza A ◽

Respiratory Infections ◽

Influenza B Virus ◽

Influenza B ◽

Virus Infections ◽

Syncytial Virus ◽

One Year

SUMMARYAmong 741 children under 5 years admitted to hospital with respiratory infections during two winters, infection with influenza A virus was diagnosed in 70 (9%), with influenza B virus in 8 (1%), and with respiratory syncytial virus (RSV) in 259 (35 %). Both influenza virus and RSV infections were diagnosed most frequently in children under the age of one year, and diagnosed more frequently in males than females. Influenza illnesses were more severe in boys than girls. Both infections occurred more often, but were not more severe, in children from a conurbation than in those from ‘rural’ areas. Convulsions were the cause of 36% of admissions with influenza A infections, but were rare in RSV infections. Bronchiolitis was the reason for 39% of admissions with RSV infections, but was rare in influenza infections. It is suggested that infants admitted to hospital are a good source of influenza virus strains for monitoring arttigenic variation.

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DRIFT OF INFLUENA A(H3N2) VIRUS: BIOLOGICAL, ANTIGENIC AND GENETIC PROPERTIES IN EPIDEMIC SEASON 2016-2017 IN RUSSIA AND COUNTRIES OF THE NOTHERN HEMYSPHERE

Voprosy Virusologii ◽

10.18821/0507-4088-2018-63-2-61-68 ◽

2018 ◽

Vol 63 (2) ◽

pp. 61-68 ◽

Cited By ~ 1

Author(s):

D. K. Lvov ◽

E. I. Burtseva ◽

E. S. Kirillova ◽

L. V. Kolobukhina ◽

E. A. Mukasheva ◽

...

Keyword(s):

Influenza Virus ◽

Northern Hemisphere ◽

Influenza A ◽

H3n2 Virus ◽

Research Centre ◽

Federal State ◽

Influenza B Virus ◽

Influenza B ◽

Epidemic Season ◽

B Virus

The article presents the features of the influenza virus circulation for the period from October 2016 to May 2017 in some territories of Russia collaborating with the D.I. Ivanovsky Institute of Virology, Federal State Budgetary Institution “N.F. Gamaleya Federal Research Centre for Epidemiology and Microbiology”, Ministry of Health of the Russian Federation. One of the 2016-2017 season’s peculiarities in Russia and countries of the Northern hemisphere was the earlier start of an increase in ARD morbidity with peak indexes reached towards the end of December 2016 - January 2017. First, influenza A(H3N2) virus was predominant; then, it was followed by influenza B virus activity observed until the end of the season. The indexes of morbidity were higher than in the previous season, while the rates of hospitalization and mortality were lower, lethal cases being detected in persons 65 years old and older. Epidemic strains of influenza A(H3N2) virus belonged to 3c.2a genetic group, reference strain A/Hong Hong/4408/2014, and its subgroup 3c.2a1, reference A/Bolzano/7/2016, that are antigenically similar. Strains of influenza B virus were antigenically similar to the B/Brisbane/60/2008 vaccine virus. Strains were sensitive to oseltamivir and zanamivir. The share participation of non-influenza ARI viruses was similar to preliminary epidemic seasons. WHO has issued recommendations for influenza virus vaccines composition for 2017-2018 for the Northern hemisphere.

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Prevalence of Influenza Virus Type and Subtype at Siriraj Hospital, Bangkok, Thailand During 2013 - 2017

Ramathibodi Medical Journal ◽

10.33165/rmj.2020.43.3.241918 ◽

2020 ◽

Vol 43 (3) ◽

pp. 1-7

Author(s):

Nattapol Narong ◽

Siriwat Manajit ◽

Sirikarn Athipanyasil ◽

Niracha Athipanyasilp ◽

Ruengpung Sutthent ◽

...

Keyword(s):

Influenza Virus ◽

Virus Infection ◽

Influenza A ◽

Influenza Virus Infection ◽

Respiratory Illness ◽

Influenza B Virus ◽

Influenza B ◽

Influenza A H1n1 ◽

B Virus ◽

Siriraj Hospital

Background: Influenza A (pandemic and seasonal H1/H3) and influenza B viruses were the predominant circulating seasonal influenza strains. Following its massive outbreak in 2009 globally, including Thailand, influenza A (H1N1) pdm09 viruses have replaced the previous seasonal H1 strain and become one of the circulating strains ever since. Both influenza A and B viruses are highly contagious and potentially cause respiratory illness ranging from mild to severe. Objective: To determine the prevalence of types and subtypes of circulating influenza virus strains in Bangkok, Thailand during 2013 - 2017. Methods: The 4385 nasopharyngeal wash specimens were collected from patients presented with influenza-like illness from January 2013 to December 2017 at Siriraj Hospital, Bangkok, Thailand. Influenza virus types and subtypes were determined using real-time RT-PCR technique. Clinical characteristics of patients infected with influenza A viruses and influenza B virus were compared and analyzed. Results: Of 4385 nasopharyngeal wash specimens, the prevalence of influenza virus infection during 2013 - 2017 was 18.22% (n = 799). Of 799 influenza-positive samples, 608 (76.09%) and 191 (23.90%) samples were positive for influenza A and influenza B viruses, respectively. Most patients were presented with fever, cough, and runny nose; however, patients infected with influenza A virus generally had higher severity than those with influenza B virus infection (P < .05). Conclusions: The findings provided the characteristics of influenza virus types and subtypes at Siriraj Hospital, Bangkok, Thailand during 2013 - 2017. Sporadic cases of influenza occurred all year round, but the incidence peaked in March 2014 and August 2017. The outcomes of this study are potentially useful for prevention, treatment, and disease monitoring.

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